Treatment of patients with acute respiratory failure (ARF) involves mechanical ventilation via endotracheal intubation (INV). Noninvasive positive pressure ventilation (NIV) using the Bi-level positive airway pressure (BiPAP) can be safe and effective in improving gas exchange. The aim of the study is to assess NIV (BiPAP) as an alternative method for ventilation in ARF and to determine factors that predict the successful use of BiPAP.

Thirty patients with ARF (type I and type II) were enrolled and divided into two groups. Group I included 10 patients subjected to INV ventilation. Group II included 20 patients subjected to NIV using BiPAP. Both groups were compared regarding arterial blood gases (ABG) on admission, 30 minutes after beginning of ventilation, at 1.5 hours and then once daily. Complications, namely ventilator-associated pneumonia (VAP), skin necrosis and carbon dioxide narcosis, static compliance and resistance, were measured at day 1 and day 2.

In patients with ARF, NIV was as effective as conventional ventilation in improving gas exchange, associated with fewer serious complications and shorter stay in intensive care. A 1.5-hour trial with NIV can predict success with BiPAP, as shown by an improvement in pH and PCO2 and the overall clinical picture. PCO2 after 1.5 hours could be the sole predictor of successful NIV with 100% specificity.